Category: Heating Systems

Combi boilers, central boilers, heat pumps and underfloor heating — comparisons and field notes from real installations.

  • Combi Boiler, Condensing Boiler or Heat Pump?

    A heating decision is one a home — or a building — will live with for at least ten years. Pick the wrong appliance and it shows up every winter on the bill and at every service visit. To pick the right one you need to know all three candidates properly: the combi boiler, the condensing boiler and the heat pump. We install all three regularly, and we know from site work where each of them wins.

    The combi boiler: the standard for an apartment

    A gas combi boiler is the default answer at apartment scale in Türkiye, and not without reason: the first cost is reasonable, installation is quick and service is available everywhere. If you are buying today, choose a condensing model without hesitation — because it recovers the heat in the flue gas, it saves a meaningful amount of fuel compared with a conventional unit. The thing to watch is capacity: a boiler chosen oversized “just to be safe” short-cycles and runs inefficiently.

    The condensing boiler: the answer at building scale

    Once you are talking about a block, a residential complex or a commercial building rather than a single flat, the nature of the job changes. A central boiler system heats from one point at high efficiency instead of dozens of independent combis; maintenance happens in one place and the flue problem is solved in one place. With a cascade arrangement the capacity is staged to match demand: at low load one boiler runs, at peak they all come in. Evening out the comfort differences between flats then comes down to heat cost allocators and hydronic balancing.

    The heat pump: the running-cost champion

    A heat pump runs on electricity but it is not an electric heater; it moves heat in from the outside air. Producing 3-4 kW of heat for every 1 kW of electricity it consumes (a COP of 3-4) puts its running cost level with natural gas and, in most scenarios, ahead of it. On top of that it cools in summer. It gives its best results with low-temperature systems such as underfloor heating. In areas with no gas infrastructure it has no real competition. We have collected the installation details for Ankara on our heat pump page.

    Side by side

    CriterionCombi boilerCondensing boilerHeat pump
    First costLowMedium (per building)High
    Running costMediumMedium-lowLow
    ScaleFlatBuilding / complex / commercialFlat, villa, commercial
    CoolingNoNoYes
    Best pairingRadiatorsRadiators + balancingUnderfloor heating / fan coils

    A practical decision guide

    • Living in a flat with gas available: a condensing combi is the safe choice.
    • Managing a building or complex: a central condensing boiler plus hydronic balancing.
    • Building a new villa or detached house: think seriously about a heat pump with underfloor heating; over the long run this is the cheapest to operate.
    • No gas infrastructure: the heat pump is effectively the only sensible candidate.

    Whatever the point you are stuck on, we would rather come out for a survey and talk in firm numbers based on the building’s heat load — not “in our opinion”, but “according to the calculation”.

    Ask for a free site survey and a capacity calculation for your project.
    WhatsApp / Phone: (0501) 557 80 89 • bilgi@projenza.com

    Projenza Engineering and Energy Solutions — an Ankara-based mechanical installation and energy company. About UsServicesProjects • References

  • Underfloor Heating or Radiators? An Honest Comparison

    “Underfloor heating is comfortable but expensive; radiators are cheap but they will do” is the most common and the most incomplete summary of this subject. The real picture changes with the building, the way it is used and the heat source — and sometimes the right answer is to use both together.

    Comfort: two different sensations of warmth

    A radiator heats the air starting from the wall it sits on; the warm air rises and the room heats “from the top down”. Floor level is usually the coolest zone. Underfloor heating does the opposite: the whole floor works as one wide, mildly warm surface, the heat starts at your feet and spreads evenly through the room. A room at 20-21°C with underfloor heating feels the same as a room at 23°C with radiators — and those 2-3 degrees are fuel saved directly.

    Efficiency: the mathematics of low temperature

    A radiator typically wants water at 55-70°C; underfloor heating runs at 30-40°C. As the water temperature falls, a condensing boiler condenses more effectively and the COP of a heat pump climbs. That is why, if you are installing a heat pump, underfloor heating is not a “preference” but a precondition of efficiency. Even paired with a combi boiler, underfloor heating delivers measurable savings over a season.

    Cost and feasibility

    CriterionUnderfloor heatingRadiators
    First costHigher (screed + pipe + manifold)Lower
    Retrofitting an existing homeNeeds floor height and renovationInstalled without renovation
    Running costLow (low water temperature)Medium
    Response timeSlow to warm, holds for a long timeWarms fast, cools fast
    AppearanceInvisibleTakes up wall surface

    The difference in response time has to match how the space is used: in homes that are lived in all day the thermal inertia of underfloor heating is an advantage; in spaces used for a couple of hours a day the speed of a radiator is what you want.

    Using both: the smartest solution on most projects

    Underfloor heating in the living room and bedrooms, a towel radiator in the bathrooms, radiators in rarely used spaces — this is the combination we install most often. Housing circuits that want different water temperatures in the same system runs through the right manifolds and control equipment together with mixing valves, and circuit balance is established with balancing valves.

    If you are curious about the installation side, we have set out the process step by step on our Ankara underfloor heating page.

    Ask for a free site survey and a capacity calculation for your project.
    WhatsApp / Phone: (0501) 557 80 89 • bilgi@projenza.com

    Projenza Engineering and Energy Solutions — an Ankara-based mechanical installation and energy company. About UsServicesProjects • References

Teklif Al